Which element has the same number of valence electrons as chlorine (Cl)?

7 N - Nitrogen. From the above electron configuration of chlorine,we see that chlorine has 7 valence electrons in its valence shell.

Explanation:

Valence electrons are the number of electrons present in the outermost shell of an atom. The last shell of a chlorine atom has 7 electrons in it. Therefore, there are 7 valence electrons in an chlorine atom.